Research On Transaction Slip Signature Algorithm Of Two Types Of Cryptocurrencies

In recent years,cryptocurrencies such as Bitcoin and Libra with blockchain as the underlying technology have set off a wave of digital economy.Bitcoin and Libra are respectively the representatives of cryptocurrencies based on the public chain and the consortium chain.Digital signature technology ensures the verifiability and integrity of the transaction content transmission process in the process of cryptocurrency transaction,the private key ensures the ownership of cryptocurrency assets.If the private key is lost or stolen,the security of cryptocurrency assets will be greatly threatened.Elliptic curve digital signature algorithm(ECDSA)has been widely used due to its short signature length advantage under the same security level,for example signing bitcoin transactions.However,the snowden incident revealed the fact that certain cryptosystems were indeed subverted.Whether the ECDSA signature algorithm can be subverted and how to resist this attack remain a challenge.Compared with ECDSA signature algorithm,Edwards curves digital signature algorithm(EdDSA)has the advantages of faster calculation speed,smaller key and signature space,and is widely used in the signature of Libra transactions.However,as a deterministic signature algorithm,it is vulnerable to differential fault attacks resulting in key loss and leakage.How to ensure the security of the EdDSA signature private key to protect the security of Libra assets is also one of the challenges facing today.Therefore,in order to protect the security of the private key of signature and prevent the attacks of analysis,tampering and replacement of the transaction signature algorithm in cryptocurrency.This thesis conducts research on the effective attack and prevention technology of transaction single signature algorithms in Bitcoin and Libra two types of cryptocurrencies.The contributions of this thesis are as follows.Subversion attack and improvement of ECDSA signature algorithm for Bitcoin transactions.Firstly,we show how to use a pseudorandom function to calculate a special random value to replace the randomness used in the ECDSA signature,realize the subversion of ECDSA signature,and prove the key extraction and undetectability security of subverting the ECDSA signature scheme.Secondly,in order to resist subversive attacks,we use the hash value of private key,message,and the random signature component as the second random number to improve the ECDSA signature scheme.As a result,the signature scheme against subversion-resistant attack is proposed.Even an adversary replaces the component of the new signature algorithm,it cannot extract any information of the signing key.Finally,we implement the proposed algorithm and existing algorithm,the implementation demonstrates that the proposed scheme has advantages in terms of computational complexity and efficiency.Analysis and improvement of EdDSA signature algorithm for Libra stablecoin transactions.We analyze the EdDSA signature algorithm with the help of differential fault attack technology,propose an EdDSA signature scheme that resists differential fault attacks,analyze the security of the scheme,and prove that the scheme satisfies the existence of unforgeable under adaptive selection message attack(EUF-CMA)and resists to differential fault attack.Then,inspired by the two-party cooperative ECDSA signature algorithm proposed by Lindell et al,based on the hybrid model of universal composable(UC)security framework and Paillier homomorphic encryption technique,we design a two-party cooperative EdDSA signature scheme against differential fault attack,and prove the security of the scheme under the hybrid model.Finally,we implement the two-party cooperative ECDSA signature algorithm and the two-party cooperative EdDSA signature algorithm against differential fault attack,and the implementation demonstrates that the proposed scheme has advantages in terms of computational complexity and efficiency.